My old Coleman AC on my 83 Excella has developed a problem. After running fine for extended periods, days even, it will emit a shuddering “Brrrrrgh!” and shut down. Checking the voltage at the unit reveals 122 volts. Even jumping around the switch accomplishes nothing. Not anything works, not the fan, the heater, or the compressor. After sitting twenty minutes or so, it will come back to life. This has happened a couple of times (that I know of). Has anyone else experienced anything like this?
You may have a termal swich on your compresor that is defective or the compresor may be bad. Normaly on a cooling unit there is a termal swich which keeps the defective motor from caching fire or blowing out your breakers. You schould check your voltage when the unit is running and if you have a amp meter measure the current draw.
Good luck Russell in hot Tucson Az. Wating for the monsoon.
... After running fine for extended periods, days even, it will emit a shuddering “Brrrrrgh!” and shut down. ...
Sounds like the overtemp sensor mounted on the compressor shut down your party. I think you're running low on freon.
The compressor's load will vary with respect to the outside temperature. If the day, in itself, is somewhat comfortable, the compressor does not have a hard time keeping your Airstream's interior cooled to your liking. But if the day is a bit on the hot side, the compressor will not be cooled by the return of "not real hot" freon.
I think you need freon. The problem is that very few people will service RV air conditioners. Unless you're lucky to find someone like Johnny, you may have to replace your AC.
Sounds like the overtemp sensor mounted on the compressor shut down your party. I think you're running low on freon.
The compressor's load will vary with respect to the outside temperature. If the day, in itself, is somewhat comfortable, the compressor does not have a hard time keeping your Airstream's interior cooled to your liking. But if the day is a bit on the hot side, the compressor will not be cooled by the return of "not real hot" freon.
I think you need freon. The problem is that very few people will service RV air conditioners. Unless you're lucky to find someone like Johnny, you may have to replace your AC.
Tom
Thanks Russell and Tom,
That’s about what I thought. I want it gone, I want it gone, but it’s also time to pay the car insurance. On hot sunny days, the interior is the same temp as outside. I want to replace it with a 15,000 btu Carrier heat pump, but finances dictate otherwise, at least for the short run. My brother and I could service the unit, he even has a bottle of Freon in reserve, but I really don’t want to go to the trouble of adding taps to the lines. I just don’t think it’s big enough for my Airstream.
I have an old Coleman also that does some similar things. Lucky to find a guy in a nearby small town that has worked on them for years. He advised that before I bring it in (and spend money on it) we should take the cover off and clean everything throughly. Said even a few leaves in the wrong spot can cause enough of a hot spot to shut the unit down. His next thought (as mentioned above) was - low on freon.
A similar sized non-heat pump Carrier is several hundred dollars cheaper.
Hi Terry,
I looked at those too. Here in Arkansas, the heat pump would take care of most of my heating needs. For colder nights, I have a stand up electric heater. Given the price of propane, I really try to avoid burning it.
Quote:
Originally Posted by Ganglin
Vaughan,
I have an old Coleman also that does some similar things. Lucky to find a guy in a nearby small town that has worked on them for years. He advised that before I bring it in (and spend money on it) we should take the cover off and clean everything throughly. Said even a few leaves in the wrong spot can cause enough of a hot spot to shut the unit down. His next thought (as mentioned above) was - low on freon.
Hi Gary,
Excellent point. I have “fixed” more than one home refrigerator by vacuuming the coils.
My old Coleman AC on my 83 Excella has developed a problem. After running fine for extended periods, days even, it will emit a shuddering “Brrrrrgh!” and shut down. Checking the voltage at the unit reveals 122 volts. Even jumping around the switch accomplishes nothing. Not anything works, not the fan, the heater, or the compressor. After sitting twenty minutes or so, it will come back to life. This has happened a couple of times (that I know of). Has anyone else experienced anything like this?
Thanks
Vaughan
An AC compressor, if low on freon, will overheat, causing the shut down.
I would suggest that you have someone that is familiar with RV AC';s, put some gauges to it.
They will know what the proper pressures should be, which is a function of the ambient temperature as well.
Tomorrow, if not raining, I will pull the cover and do the general cleaning. I'll get my special custom Airstream ladder (extension ladder with two old bath towels duct taped on each side) and get to work. I’ve done automotive AC work, and own two sets of gauges. I am familiar with the process and the ambient air conditions. Do you know which refrigerant Coleman used in them?
I will keep everyone updated on this. Maybe I’ll get lucky and there will be a big nest blocking the flow.
Maybe I’ll get lucky and there will be a big nest blocking the flow.
Well, just finished removing the cover and checking for obstructions. Only 1 small dirt dauber nest on the very top of the compressor. Washed everything anyway.
It did give me a chance to oil the fan. The plastic plugs in the oil lines broke and fell away, so I decided to make replacements by squirting a tiny amount of silicone seal on the top. Ordinarily I would never put silicone seal where it would be potentially difficult to remove, but hey, I just flooded the things with 20 weight Mobile 1. There’s no way it’s going to stick. I kind of smeared it off to the side to create little pull handles.
The nests I did discover was a big nest of the large red wasps in my front vent and a nest of the smaller, less aggressive, red and black wasps in the belly pan by the steps. After dealing with them, there are still a few survivors buzzing by. I decided that replacing the cover could wait till tomorrow when things calm down a bit.
I think the next step will be replacement with a 15,000 btu heat pump as soon as financially possible.
A simple overload cutoff at the compressor would not effect the fan.
After the unit shuts down and the fan will not work will the fan work an hour after the AC has shut down. I ask this because if a unit is low on gas and in high humidity it will freeze over the coils and if this ice gets enough it could touch the fan and thus the noise you hear. Once the fan stops the compressor would soon go out on overload. If the unit sits for an hour and then the fan will run I would look for ice on the face of the coils the next time you run it. Just remove the filter and look up at the coils.
As long as you have the cover off you can do a simple check as to the charge. Start the unit and after a few minuits touch the larger of the 2 lines at the compressor. This line should be cold and if the humidity is high it may be wet. If not cold or wet but warm you have a problem, low charge or leaking valve in the compressor. Don't touch that small line. It will be hot.
That old a unit most likely has a piston compressor. The newer units a rotory and much quiter. That is it's self may be a good reason to upgrade.
A simple overload cutoff at the compressor would not effect the fan.
After the unit shuts down and the fan will not work will the fan work an hour after the AC has shut down. I ask this because if a unit is low on gas and in high humidity it will freeze over the coils and if this ice gets enough it could touch the fan and thus the noise you hear. Once the fan stops the compressor would soon go out on overload. If the unit sits for an hour and then the fan will run I would look for ice on the face of the coils the next time you run it. Just remove the filter and look up at the coils.
As long as you have the cover off you can do a simple check as to the charge. Start the unit and after a few minuits touch the larger of the 2 lines at the compressor. This line should be cold and if the humidity is high it may be wet. If not cold or wet but warm you have a problem, low charge or leaking valve in the compressor. Don't touch that small line. It will be hot.
That old a unit most likely has a piston compressor. The newer units a rotory and much quiter. That is it's self may be a good reason to upgrade.
Hi HowieE,
Good suggestions, but it’s not like an ice buildup. The sound to shutoff is only a couple of seconds. Coil freeze over is an excellent indicator of low Freon since the low size pressure of R12 almost exactly coincides with Fahrenheit temperature of the resulting gas in the evaporator. You usually fill till the low side is 30 or 31 degrees to prevent freezing condensation. I am not getting freeze up, so I am a little skeptical of the low Freon guesses. Could be wrong, though. I was also concerned about the fan being shut off by a compressor shutoff. Didn’t make sense.
Great looking rig! I looked at your website. Dual fuel, huh, cool beans! Haven’t seen anything like that in years! Back in the 80s I rebuild irrigation engines in the Texas panhandle. Most of the stuff was Minneapolis Moline HD 800s, 800 CID natural gas burning 6 cylinders. We were also an Allis Chalmers dealership. Many of the Allis diesels were fitted with propane carbs and connected to natural gas or propane. You don’t have to even readjust the carb to switch from one to the other. They made tremendous power. A legendary embarrassing event occurred before I started there. They had completed a dual fuel conversion on a new Allis engine and a factor rep was there taking photos. The engine was hooked to a 600 hp tractor dyno. One of the shop owners richened the natural gas mixture, and the engine ran away-pegging the dyno and even flattening the tire on one side and lifting the other off the shop floor on the other. Just as it appeared that the engine was going to start spinning the dyno, someone stomped on the natural gas line and got things under control.
I think I need a bigger, newer unit anyway. Since you have a properly sized unit, how does your AC cool your AS? It really gets hot here, and I’m thinking a 15,000 btu AC is what I need anyway.
I tend to agree with Howie, all of the units I have messed with have the thermal shutoff at the compressor, it wont shut down the fans. Mine had a bad circuit breaker and did the unpredictable so I would swap a $5 breaker and see where it went.
Then again, I can see that your are looking for the forum to support the purchase of a new larger AC, go for it. Your old one is probably on it's last leg
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Checking the voltage at the unit reveals 122 volts. Even jumping around the switch accomplishes nothing. Not anything works, not the fan, the heater, or the compressor. After sitting twenty minutes or so, it will come back to life. This has happened a couple of times (that I know of). Has anyone else experienced anything like this?
Hi,
I was also concerned about the fan being shut off by a compressor shutoff. Didn’t make sense. 
Haven’t seen anything like that in years! Back in the 80s I rebuild irrigation engines in the Texas panhandle. Most of the stuff was Minneapolis Moline HD 800s, 800 CID natural gas burning 6 cylinders. We were also an Allis Chalmers dealership. Many of the Allis diesels were fitted with propane carbs and connected to natural gas or propane. You don’t have to even readjust the carb to switch from one to the other. They made tremendous power. A legendary embarrassing event occurred before I started there. They had completed a dual fuel conversion on a new Allis engine and a factor rep was there taking photos. The engine was hooked to a 600 hp tractor dyno. One of the shop owners richened the natural gas mixture, and the engine ran away-pegging the dyno and even flattening the tire on one side and lifting the other off the shop floor on the other. Just as it appeared that the engine was going to start spinning the dyno, someone stomped on the natural gas line and got things under control.
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